CORE D: DESCRIPTION (provided by applicant): The CFAR Flow Cytometry Core is heavily used by investigators in all programs of the Center. The core promotes application of flow cytometry in HIV research by providing education on this powerful technology and consultation with investigators on the planning of research projects and the design of proposed experiments. The core is state-certified for 4-color lymphocyte immunophenotyping in clinical testing and has accrued an extensive array of conventional and innovative methodologies in its research repertoire. Our instrumentation consists of 2 FACScans for 3-color detection, 2 FACSCaliburs for 4-color detection, and a FACSVantage SE located in a BL-3 level laboratory. It is equipped with 3 lasers for 7-color detection, a biohazard containment unit, a cell deposition unit, and an isotemp recirculator for the sorting and cloning of cells exposed to HIV and other infectious microbes. Charge-back fees to scientists using this facility provide recovery of costs not covered in the proposed budget.